Electromagnetic structure for circuit breakers



Feb-25, 1947. w, sco JR 2,416,458

ELECTROMAGNETIC STRUCTURE F OR CIRCUIT BREAKERS Original Filed Jan. 5, 1941 INVENTOR.

W ATTOPNEY.

Patented Feb. 25, 1947 ELE-GTRGMAGNETIC STRUCTURE FOR CIRCUIT BREAKERS William M. Scott, 1113, Bryn Mawr, Pa., assignor to I. T. ExGircuit-Breaker Company, Philadelphia, Pa a corporation of Pennsylvania Original application January 3,1941, Serial No.

1944, Serial No. 534,456

1 Claim.

My invention relates in general to the field of circuit interrupters and more specifically concerns a novel and improved form circuit breaker and a control means therefor. This case is a division of my application Serial No. 373,051, filed January 3, 1941, and entitled Circuit interrupter and control therefor.

An object of my invention is to provide a novel circuit breaker in which the electromagnetic winding is split into pluralities of parallel conductors encasing the magnetic coil.

Figure 1 is a fragmentary side view of one of the circuit breaker units illustrating the arc quencher in its raised position.

Figure 2 is a fragmentary cross-sectional View of the magnetic blow out coil taken on line 2-2 of Figure 1.

Referring now to the drawings, an arc quenching unit 45, preferably of the magnetic blow out type, is provided for each of the circuit breaker poles. It is mounted upon the stationary contact and blow out coil assembly which is supported upon the insulated cross-bars 25 by means of metallic blocks 46.

Associated with the arcing chamber is a stationary contact 5! which is engageable by a plurality of complementary movable contacts 52. The details of this structure are more fully described in the parent application referred to above.

The are quencher 45 as illustrated is of the well known magnetic blow out type. Essentially this structure comprises a pair of parallel insulating plates 202 spaced by end insulating members.

The interior of the arc quencher 45 may have any suitable arc extinguishing construction such as .that shown in the parent application.

Mounted upon the sides of the arc quenching structure are a plurality of magnetizable members 213 formed from magnetic laminated material and each communicating with and connected to a central magnetic member 212 by means of the bolts 2 I 0 passing through extensions 214. The magnetic members 213 are positioned against the side insulating plates 202 by means of a plurality of straps 215 fastened thereto by the bolts 201.

The entire structure is pivotally mounted, by means of a pair of plates 220, which are secured to the walls of the arc quenching structure upon a shaft 211 which in turn is supported by means of the metallic brace 221.

The magnetic members 211-213 are magneti- Divided and this application May 6,

2 cally energized by means of a coil 216 which is supported upon the insulated cross-bars 25.

The coil 216 is a double turn of copper of rectangular cross-section through which the line current flows. The current enters from the bus bar 226 which is fastened directly to one section 221 of the coil 216. This section 221 passes completely around. a rectangular magnetic core 231 and then branches out at 232 into two parallel sections 233 and 234 which again pass around the core 231. Each of these two sections then branches out again at 235 and 236 into two additional sections 231 and 238 and upon completing their half circuit about the core are joined together at 241.

This novel arrangement thus provides the equivalent of two complete turns about the magnetic core 231. The individual turns of the coil are braced by the insulating bolts 2 33 which pass through aligned perforations 244.

The core 231 is formed from a series of stacked rectangular laminations of some magnetic material such as soft iron clamped together by means of the bolts 251.

These laminations are stacked with their poles to form a U-shaped magnet having the two side members 252 extending from the central core 231. These side members as illustrated come into close frictional contact with the central magnetic structure 212 supported upon the sides of the arcing chamber.

Thus when the arcing chamber is lowered, energization of the core 231 by the line current flowing through the coil 216 will cause the magnetization of all of the members 212, 213 which are strapped to the sides of the arcing chamber to produce a transverse magnetic field across the arc quencher.

The magnetic core 231 is wrapped with an insulating material 253 to preclude the short circuiting of the turns of the coils 216.

The coil 216 terminates in the extension 241, the stationary contact is supported thereupon by means of a plurality of bolts which pass through countersunk perforations therein and engage correspondingly threaded perforations in the extension 241.

A plurality of projections 255 and 255 are provided upon the coil 216 in order to properly position the coil and the attached arcing chamber upon the plate 222,

The material utilized for the coil is preferably a highly conductive one such as copper, the crosssectional area of which is selected to carry normal load currents at standard temperature rise.

plurality of sections and passing around said 15 2,311,690

core, and reuniting to form a winding section for said core.

WILLIAM M. SCO'I'I, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,155,626 Steen Oct. 5, 1915 1,560,553 Evans Nov. 10, 1925 1,988,927 Tritle Jan. 22, 1935 2,215,797 Sauer Sept. 24, 1940 Pokorny Feb. 23, 1943 

